사질토 지반의 토조실험을 통한 보강된 말뚝기초의 수평거동 분석 = Lateral Behavior of Reinforced Group Piles in Sand from Model Pile Tests

다국어 초록 (Multilingual Abstract)

In this study, a series of model pile tests were performed to investigate the lateral behavior of reinforced group piles in sand. The group pile consisted of four piles with same dimension was reinforced by piles which have different stiffness and dimension (diameter and length) from those of the group piles. Reinforcing effects of reinforced group piles were evaluated by comparing the ultimate lateral resistances and maximum moments with and without using reinforcing piles for an existing pile group.
The result of model group pile test without reinforcement showed the group efficiency of 0.68 due to the group effects caused by shadowing effects, edge effects, and gap behind pile. The maximum moment obtained from the pile in the front raw was greater than that in the back raw.
The results of tests for single pile (d=40 mm) reinforced with a pile (d=20 mm) showed that the group efficiency of the reinforced pile depended on the center-to-center distance between piles and the load direction. The maximum moment obtained from the reinforced pile was comparable to that from the single model pile test.
From test result for the 2X2 group pile (d=40 mm) reinforced with eight piles (d=20 mm), the ultimate lateral resistance increased by 30% and the maximum moment decreased by 37%.
For the cases of the group piles reinforced with large diameter piles (d=40, 60 and 80 mm), obvious increases in the ultimate lateral resistance were not shown. The ultimate lateral resistance of the reinforced group piles depended on the direction of load. However, reinforcing effects for the maximum moment (32~46% decrease) of the reinforced group pile was obvious.

목차 (Table of Contents)

• Ⅰ. 서론 1
• 1.1 연구개요 1
• 1.2 연구의 필요성 및 목적 3
• Ⅱ. 횡하중을 받는 말뚝의 해석 5
• 2.1 극한평행법 5
• 2.2 탄성지반반력법 10
• 2.3 p-y 곡선법 16
• 2.4 군말뚝 18
• 2.5 변형률 쐐기파괴 이론 21
• Ⅲ. 실내모형토조 실험 27
• 3.1 모형토조 제원 27
• 3.2 주문진표준사의 역학적특성 29
• 3.3 모형말뚝 제원 34
• 3.4 실험방법 40
• Ⅳ. 실험결과 및 고찰 45
• 4.1 단말뚝 실험결과 45
• 4.2 군말뚝 실험결과 53
• 4.3 보강군말뚝 실험결과 59
• 4.4 보강말뚝의 효율 및 정량화 79
• 4.5 결론 84
• 참고문헌 86
• ABSTRACT 90